1. Field of the Invention
The invention relates to an apparatus and method for sequentially xerographically copying a plurality of manually manipulated documents and, in particular, relates to an apparatus and method for facilitating the copying of pages in a book by controlling operation of a xerographic machine to allow manual disposition of sequential pages while the machine remains in an operating condition.
2. Description of Related Art
In known xerographic copying machines, the process copying an original document disposed for copying involves electrostatically charging a photoconductive surface and moving the charged surface to a position where it is exposed to a light image of the original document for selectively dissipating the charge to form a latent electrostatic image of the original on the surface. The surface bearing the latent image is then moved to a developing station at which a developer mix or toner is applied to the surface rendering the latent image visible. The surface bearing the now-visible image thereafter is moved to a transfer station for contact with a sheet of support material, usually paper, which simultaneously has been fed from a supply to the transfer station. The sheet of support material to which the image has been transferred is then moved to a fusing station at which the image is fixed and thereafter is fed to an output stacker.
After the transfer station, the photoconductive surface is moved to a cleaning station at which toner is removed and the surface is electrically neutralized in preparation for a subsequent copying process.
The light image of the original document is generated by various known methods. One method includes a flash of light which conveys a reflection of the document to the charged surface through conventional stationary optics. Another method uses a light scanning system. Other methods may include laser scanning.
The copying process of a xerographic machine requires certain preparatory steps to achieve a copy ready state before the sequential copying steps can begin. These preparatory steps include preparing the photoconductive surface, charging the light source for generating the light image, moving the prepared photoconductive surface to the imaging station, and feeding a support material to the transfer station. The subsequent copying steps include creating the light image and transferring it to the prepared photoconductive surface, performing the subsequent developing step, transferring the developed image to the support material, and feeding the support material to the stacker.
A xerographic machine when not in use normally is in a standby condition. As used herein, the standby condition is a fully powered condition requiring only actuation of a start switch to begin the copying process. The standby condition, sometimes called a cycle out condition, is distinguished from a power saver mode available on some machines. On manual actuation of the start switch, the machine cycles to an operating condition and performs the preparatory steps and once the copy ready state is achieved the copying steps are immediately begun. The machine includes a timing circuit to control each subsequent series of copying steps in order to allow time for the preparatory steps. Once the copy ready state is achieved, the machine awaits a command before commencing the subsequent series of copying steps. A counter will issue an automatic command where multiple copies of an original have been selected. Where a plurality of original documents have been disposed in an automatic feeder, an automatic command is issued on placement by the feeder of each original in position for copying. Absent such an automatic command, a manual command generated by re-actuation of the start switch is necessary to commence the copying steps. The machine includes a standby control which automatically cycles the machine to the standby condition if a predetermined time elapses without re-actuation of the start switch.
Efficient copying is difficult where a plurality of original documents are manually disposed for copying, a problem most often present when multiple pages of a bound book or document are to be copied. While reference to copying pages of a book or bound document is made throughout the specification, the invention is not so limited and may be used to copy various types of original documents. When the process of copying the first page of a book or document is complete that page must be turned so that the next can be manually disposed in position and the start switch depressed before the machine cycles to the standby condition. The next document or page must be in the proper position before the start switch is depressed since the machine will have achieved the copy ready state and on actuation of the start switch the copying steps will begin immediately. Since the delay before the machine cycles to the standby condition is relatively short, the machine frequently cycles to the standby condition before the next page can be disposed for copying. Subsequent actuation of the start switch will require the machine to cycle to the operating condition and achieve the copy ready state before copying of the next document can begin. To the operator this is a frustrating delay and to the machine this causes unnecessary operations resulting in undue wear on the components.
The invention provides an improved xerographic machine and related method for controlling the operation of sequential copying processes to permit manual disposition of subsequent documents or pages in position for copying without the machine cycling to the standby condition.
The invention provides for selective introduction of a delay, either fixed or variable, between achievement of the copy ready state and initiation of the copying steps.
Actuation of the start switch on a conventional xerographic machine generates a command for a single copying process. Thus, when copying pages of a book, the start switch must be depressed once for each page to be copied. The improved machine of the invention permits selective generation of two sequential copying processes, with a delay, either predetermined or selectively variable, between the two processes. This permits copying two adjacent pages of a book or other bound document before the machine cycles to the standby condition.
The invention alternatively provides for generation of a plurality of pairs of copying processes, the two processes of each pair being separated by a predetermined or selectively variable delay. When copying pages of a book, it frequently requires less time to position the immediately adjacent page for copying than is required to turn the page and position for copying. Thus, the invention provides for a different delay between pairs of processes, the different delay being longer to permit page turning and positioning for copying.
Additional advantages of the invention are set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.